So it's my first post here, and I apologize for it being a long one, but I've got a lot to say and ask.

Several years ago I bought my first good set of headphones, the Sennheiser HD 555's for about $80 new and foam modded them. They were really cheap at the time. Unfortunately, over the course of time, they started cracking at both sides of the headband, much like in this picture.

This is a really common problem with them. For me, it happened whenever I'd turn the cups even a little, which was almost unavoidable. Eventually, more chipped off and caused noticeable cosmetic damage and it was apparent that the headphones were about to disassemble themselves. I gave it about a day to a couple weeks before they were unusable.

When I picked them up the next day, one of the cups had completely fallen off and was hanging by a wire. The drivers are fine, they work great, but the headphones are unusable because the cheap plastic just couldn't last.

I enjoyed the sound quality quite a bit overall considering they were my first good headphones, but I was left wanting more at times and the bass felt underwhelming. I'm not terribly concerned with bass in the first place, but I just can't help but feel it was a decent bit below the quality of everything else.

This time, I'm looking to spend a bit more money, but I'm not sure what to get or what I should be expecting. I was looking at Sennheiser HD 650's, but they're definitely on the high end of how much I want to spend on headphones at what seems like about $400 new and I fear they might fall apart the same way the 555's did. Even worse, I've been seeing online at various places like Head-Fi that I would "need" to get a $500 amp along with it! That's absurd and is beginning to approach the cost of the much more expensive HD 800 when you add them up. I don't know almost anything about amplifiers, but it seems ridiculous to me that anyone could suggest an amplifier that is nearly as much as, or in this case more expensive than, the headphones themselves! Do they truly make that much of a difference, or are they only something people should bother with if the volume isn't loud enough?

Are there any other suggestions for good headphones in the $200-350 range? What should I be expecting from what I get? Are the 555's about what $200 headphones should sound like now that they're at that price, or were they more what good $100 headphones should sound like? Will I see a noteworthy (read: audible) increase in quality now that I'm willing to spend a good bit more? Are there any other "tricks" that make the headphones currently selling sound better than they were intended to?

I'm mainly going to be listening at home, on my computer, and sound leakage isn't really an issue to me. 95% of the time, there's practically no sound going on around me, but I'm still kinda willing to go with a set of closed headphones because it can be quite annoying when there is, so if a particularly outstanding set is within that price range, I'd be more than willing to settle with them. I am not interested in earbuds of any sort and I primarily listen to rock/metal and electronica. Generally stuff more along the lines of house and trance rather than dubstep. I'm almost never going to be listening to anything less than 256kbps mp3s and a lot of my active listening will be with FLACs. I would much prefer to hear things as accurately as possible, even if that's caused a decent bit of frustration with the occasional set of fake 320kbps mp3s and low quality studio recordings.

I've done a good bit of research, but I'm still somewhat lost and quite afraid of being ripped off. After finding out Sennheiser used the same drivers for an $80 product that they used in a slightly prettier $200 product and simply put a piece of foam over it to make it sound worse, I became a bit paranoid that people were regularly getting screwed if such a big name was trying to pull this off. Inbetween the highly subjective reviews from people who seem to be following the crowd of their local forum, the ridiculous and nonsensical products such as $30K headphone cables, the deceptive marketing crap, and the complicated, made up terms used to describe sound that may or may not actually mean anything, the audiophile world has been painted to me as something very shady where people may not know what's really good and what isn't until after they've spent hundreds, sometimes thousands of dollars on what could be a total scam. It's a real shame, because I, and many others, are simply normal people who want to enjoy and appreciate sound, and I'm very thankful for the fact that forums like this exist and show the other side of the coin.

With that said, a few more questions to wrap up this post.

Are "burn-ins" real? Do they actually do anything, or is it just a placebo thing? One of the main reasons I ask this is because after using these old, terrible iPod earbuds for the past few days, the sound seemed quite terrible at first but didn't seem nearly as awful after I began to adjust to it. Certainly, it's nothing like the Sennheisers and never will be, but I felt the illusion of increased sound quality despite knowing they were exactly the same.

And the last question, what exactly are DACs, in plain English? I mean, I know what they are. They convert digital to analog. I don't fully understand what that actually means, but my understanding of it is that it takes what exists digitally on something like a CD player or a hard drive and translates it to a format that allows headphones to make sound. Doesn't this happen already? So what's the point of a DAC, to make it more unfiltered than the crappy built-in ones? Are the effects of this noticeable and worth the purchase along with the kind of headphones I'd be buying?

Weird, my 555's show no signs of that particular crack, as far as I know. The hard parts are in perfect shape; it's just got completely just worn out pads (because they're approaching something like 7+ years now). And I selected them especially because of the extraordinarily punchy, physical bass, as opposed to the muddy whoomps of all the other phones I tried that day (Including some luxurious Beyerdynamic for twice the price and zero sound quality increase).

The only relevant age problem I have is that something's faintly resonating in one cup given certain bass frequencies. I'm not experienced with headphone DYI, so I do't know if it's fixable by simply glueing something in place.

QUOTE

And the last question, what exactly are DACs, in plain English?

It takes the sequence of sampled numerical values from a digital source and reconstructs the smooth signal as voltage variations that are the analog of the pressure variations of air (which is sound). These variations then interact with the speaker driver, vibrate the air and thus produce sound.

Weird, my 555's show no signs of that particular crack, as far as I know. The hard parts are in perfect shape; it's just got completely just worn out pads (because they're approaching something like 7+ years now).

Chances are yours are so old that they still date from before the Sennheiser factory fire, after which production of these models was moved from Ireland to China in a hurry. Should be nominal 150 ohm units then, easily confirmed with a multimeter. I'm guessing that the plastic used in the Chinese factory is of inferior quality.

QUOTE (dhromed @ Jul 18 2012, 10:25)

And I selected them especially because of the extraordinarily punchy, physical bass, as opposed to the muddy whoomps of all the other phones I tried that day (Including some luxurious Beyerdynamic for twice the price and zero sound quality increase).

On a low-impedance output, 150 ohm HD555s should sound almost exactly like modern-day HD598s. I found the amount of bass in these just about right on a low-impedance output, significant output impedance would probably turn them into basshead cans.

QUOTE (dhromed @ Jul 18 2012, 10:25)

The only relevant age problem I have is that something's faintly resonating in one cup given certain bass frequencies. I'm not experienced with headphone DYI, so I do't know if it's fixable by simply glueing something in place.

Usually something like this is caused by foreign objects in the driver or the foam cover, e.g. a hair. HD555s should be less susceptible to stuff getting into the drivers than my trusty HD590s, which have almost their entire driver front exposed (only covered by foam). I used to clean hair out of those quite regularly when I was younger. It seems to have gotten much less necessary, partly because I tend to be inspecting the foam before use and partly because I have (and lose) less hair nowadays.